High-definition
(HD) video refers to any video format with a resolution higher
than standard-definition (SD) video formats. Typically, standard-definition refers
to digital formats with resolutions close to those of analog TV
standards, such as NTSC and PAL (around 480 or 576 vertical lines,
respectively). The most common HD formats have resolutions of 1280 x 720
or 1920 x 1080, with a widescreen aspect ratio
of 16:9.
HD video formats include interlaced and noninterlaced varieties.
Typically, the highest-resolution formats are interlaced at the
higher frame rates, because noninterlaced video at this resolution
would require a prohibitively high data rate.
HD video formats are designated by their vertical resolution,
scan mode, and frame or field rate (depending on the scan mode).
For example, 1080i60 denotes interlaced scanning
of 60 interlaced 1920 x 1080 fields per second,
whereas 720p30 denotes progressive scanning of
30 noninterlaced 1280 x 720 frames per second.
In both cases, the frame rate is approximately 30 frames per second.
For more information on high-definition video, see www.adobe.com/go/learn_dv_primer_highdef.
Programs
in Adobe Creative Suite 3
Production Premium (Adobe Premiere Pro, Adobe After Effects, Adobe
Soundbooth, and Adobe Encore) includes presets that are designed
for working with various HD formats. Some of the most common HD
video formats you may encounter include the following:
- DVCPRO HD
-
Panasonic’s high-definition variant of its DVCPRO format,
which also includes DVCPRO25 and DVCPRO50. Whereas DVCPRO25 and
DVCPRO50 support data rates of 25Mbits/s (megabits per second) and
50Mbit/s, respectively, DVCPRO HD supports a data rate
of 100Mbit/s, from which it gets its other name, DVCPRO100.
- HDCAM
-
Sony’s high-definition version of its Digital Betacam format.
A variant called HDCAM SR uses a tape with
a higher particle density to record video with greater color sampling
and at higher bit rates. However, HDCAM SR is supported by
decks only, and not camcorders.
- HDV
-
Developed jointly by several companies, HDV employs a form
of MPEG‑2 compression to enable high-definition video to be encoded
onto standard miniDV cassette media.
- H.264
-
Also known as MPEG‑4 part 10 and AVC
(Advanced Video Coding), H.264 can deliver video over a range
of bitrates more efficiently than previous standards. For example,
H.264 can deliver the same quality as MPEG‑2 at half the data rate.
H.264 is built into the Apple QuickTime 7 multimedia architecture,
and it’s supported by both HD‑DVD and Blu‑ray Disc, two newer DVD
formats.
- Uncompressed HD
-
High-definition video in an uncompressed format. Without compression
to reduce the video’s data rate, uncompressed video requires relatively
fast computer processors, hard disks, and a specialized capture
device.
- WM9 HDTV
-
Microsoft’s high-definition delivery format is among numerous formats
included in the Windows Media 9 (WM9) framework. By employing
an aggressive compression scheme, WM9 HDTV permits high-definition
video encoding and playback at relatively low data rates.